Laminate floors and other similar floorboards are made up of one or more upper layers of decorative laminate, decorative plastic material or wood veneer, an intermediate core of wood fiber based material or plastic material and preferably a lower balancing layer on the rear side of the core.
Laminate flooring usually consists of a core of a 6-9 mm fiberboard, a 0.2-0.8 mm thick upper decorative surface layer of laminate and a 0.1-0.6 mm thick lower balancing layer of laminate, plastic, paper or like material. The surface layer provides appearance and durability to the floorboards. The core provides stability, and the balancing layer keeps the board plane when the relative humidity (RH) varies during the year. The floorboards are laid floating, i.e. without gluing, on an existing subfloor. Traditional hard floorboards in floating flooring of this type are usually joined by means of glued tongue-and-groove joints.
In addition to such traditional floors, floorboards have been developed which do not require the use of glue and instead are joined mechanically by means of so-called mechanical locking systems. These systems comprise locking means, which lock the boards horizontally and vertically. The mechanical locking systems can be formed by machining of the core. Alternatively, parts of the locking system can be formed of a separate material, which is integrated with the floorboard, i.e., joined with the floorboard in connection with the manufacture thereof.
The most common core material is a fiberboard with high density and good stability, usually called HDF—High Density Fiberboard. Sometimes also MDF Medium Density Fiberboard is used as core. MDF and HDF contain ground wood fibers, which by means of binding agents are combined into a sheet material.
Laminate flooring and also many other floorings with a surface layer of plastic, wood, veneer, cork and the like are produced in several steps. As shown in FIG. 1a-1d the surface layer and the balancing layer is produced in a separate step and are then applied to a core material by for example gluing a previously manufactured decorative layer and balancing layer to a fiberboard. Such a production process is used when a floor panel has a surface of a decorative high pressure laminate (HPL) which is made in a separate operation where a plurality of sheets of paper impregnated with a thermosetting resin, such as melamine and/or phenol are compressed under high pressure and at a high temperature.
The currently most common method when making laminate flooring, however, is the direct pressure laminate (DPL) method which is based on a more modern principle where both manufacture of the decorative laminate layer and the fastening to the fiberboard take place in one and the same manufacturing step. One or more papers impregnated with a thermosetting resin such as melamine are applied directly to the board and pressed together under pressure and heat without any gluing.
FIGS. 1a-1d shows how laminate flooring is produced according to known technology. As a rule, the above methods result in a floor element (3 in FIG. 1b) in the form of a large laminated board, which is then sawn into several individual floor panels (2 in FIG. 1c), which are then machined to floorboards (1 in FIG. 1d). The floor panels are individually machined along their edges to floorboards with mechanical locking systems on the edges. The machining of the edges is carried out in advanced milling machines where the floor panel is exactly positioned between one or more chains and belts or similar, so that the floor panel can be moved at high speed and with great accuracy past a number of milling motors, which are provided with diamond cutting tools or metal cutting tools, which machine the edge of the floor panel. By using several milling motors operating at different angles, advanced profiles can be formed at speeds exceeding 100 m/min and with an accuracy of ±0.02 mm.
The upper edges of the floorboards are in most cases very sharp and perpendicular to the floor surface and in the same plane as the floor surface.
Recently laminate floors have been developed with decorative grooves or bevels at the edges, which looks like a real gap or a bevel between solid wood floor such as planks or parquet strips.
It is known that such edges cold be made in several different ways.
In recent years, laminate floors, which are imitations of stones, tiles and the like, have become more and more common. It is known that the method which is used to manufacture decorative edge portions of such floors could also be used to produce edge portions which look like a gap in solid wood floors. This is shown in FIGS. 2a and 2b. The starting material is a decorative paper with printed edge portions which is impregnated with melamine resin. Uncontrolled swelling takes place in this operation. In the subsequent lamination, the decorative impregnated paper is placed on a core and lamination takes place against an embossed metal sheet, which forms a depression (20) in those parts of the floor element (3) where edge portions are to be formed. This is shown in FIG. 2a. The result is a floor element (1,1′) whose front side has an embedded or embossed edge pattern corresponding to the intended edge portions between floorboards, as shown in FIG. 2b. 
This manufacturing method suffers from a number of problems, which are above all related to difficulties in positioning the decorative paper and metal sheets in connection with laminating and the difficulty in positioning floor element and floor panels in the subsequent sawing and machining of the edges. The result is a floor panel with edge portions, which show considerable and undesired variations in structure and design as shown in FIG. 2b. Another problem is that this method is only suitable for embossed textures which are less than about 0.2 mm deep and which cannot be made deeper than the thickness of the surface layer. Further disadvantages are that although the edge is below the floor surface, it is sharp and parallel with the surface.
FIGS. 2c and 2d show another method. Decorative edge portions could be made in connection with the machining of the edges of the floor panel 1, 1′. Laminating and sawing of the floor element (3) can then take place without any specific requirements as to alignment, and swelling problems do not occur. The decorative and embedded edge portion can be provided by part of the decorative surface layer being removed so that the reinforcing layer of the laminate becomes visible (FIG. 2d). Alternatively, the core (30) itself can be used to create the decorative embedded edge portion. This is shown in FIG. 3a. The surface layer has been removed and the core (30) is uncovered within areas that are to constitute the decorative edge portion (20). A decorative grove could be made on only one edge as shown in FIG. 3a. 
The most common method is shown in FIG. 3b. A part of the edge portion of a floorboard (1, 1′) has been formed as a bevel 20 and this bevel is than in a separate operation covered with a separate material such as a tape, a plastic strip or it could be colored, printed etc. Separate materials are complicated and costly to apply and it is not possible to make an edge portion with the same design and structure as the floor surface. Such edge portion has considerable lower abrasion resistance and inferior moisture properties than the floor surface. The production method is rather slow and several application unites are needed to meet the speed of a modern production line for laminate floorings.
Another method is shown in FIG. 3c. The edge portion (20) is formed in a separate material, which has been inserted or extruded into a groove. This method has the same disadvantages as the method described above.
FIG. 3d show that a rounded edge portion (20) could be produced with the well known postforming method used for furniture components. A postforming laminate surface (31) of HPL, which is so flexible that it can be formed after the production of the laminated sheet, could be glued to an already machined floorboard (1). In a second production step the edge could be heated and the laminate could be bent and glued around the edge portion. This method would be very complicated, costly and is not used in laminate floorings.
The principles of the present invention are directed to edge portions in building panels, which overcome one or more of the limitations and disadvantages of the prior art.
These and other objects of the invention are achieved by floorboards, and manufacturing methods having the features that are stated in the independent claims. The dependent claims define particularly preferred embodiments of the invention.